Known ship propulsion systems that include azimuth pod thrusters are conventionally mounted through the hull of the vessel. Azimuth thrusters are used in vessels of all sizes from ships to sports leisure boats. The thrusters are rotatable 360 degrees about a vertical axis and they are mounted to the vessel using a series of up to seven roller bearing assemblies. The thrusters may be a fixed distance from the hull or they may be retractable. The retractable thruster arrangement may be a “swing-up” action or a linear vertically retractable action. When using a series of roller bearings for the means of mounting, the overall distance of the series has to be of a certain length in order to retain a sufficient level of tolerance deviation. The necessary overall length of the series means that there is a reduced amount of area within the vessel. Alternative traditional propulsion systems include conventional transmission shafting and propellers with inclined shafts are usual. The construction of traditional propulsion systems leads to low efficiency and as a consequence, thereof also noise and levels of vibration will often be much higher than what is allowed for larger commercial vehicles. The reason for this is because the motors of the existing concepts have to be positioned forward in the boat in order to avoid too large inclination of the propeller shaft. Nevertheless, the inclination will lead to large propeller excitations as they are rotating.
The various aspects of the present invention set out to overcome the problems of the known systems by providing propulsion systems that utilize less overall space within a waterborne vessel than equivalent known propulsion systems and in particular to provide a system that requires a reduced amount of space, therefore providing more space within the waterborne vessel.